In a small new study, Parkinson’s disease patients who took caffeine pills had slight but noticeable improvements in movement problems.

The findings warrant further study, Canadian researchers said. And there are still questions – such as whether patients would develop a caffeine tolerance, eventually blunting the benefits of coffee or caffeine pills. For the new study led by lead researcher Dr. Ronald Postuma, from McGill University in Montreal, 61 people with Parkinson’s with a mean age in the mid-60s were randomly assignied to six weeks of caffeine pills or placebo. Participants in the caffeine group took 100 mg when they woke up and again after lunch for the first three weeks, then were bumped up to 200 mg twice a day for the rest of the study (A cup of brewed coffee typically has about 100 mg of caffeine).

After the study, people taking caffeine didn’t report a clear improvement in sleepiness. But that group did improve on an overall scale of Parkinson’s symptoms, including on measures of muscle rigidity and other movement problems. The average benefit was a decrease of about five points on the disease rating scale, according to findings published Wednesday in Neurology. Dr. Postuma said a typical patient who’s had Parkinson’s for a few years would have a score of 30 to 40.

About half of patients in both groups had some sort of side effects due to the caffeine or placebo pills, most commonly stomachaches.

People who drink caffeine throughout life are known to have a lower risk of getting Parkinson’s in the first place – but that doesn’t mean coffee, tea or caffeinated fizzy drinks necessarily have a direct effect on the disease and its symptoms. It could be that there are other differences between coffee drinkers and non-drinkers that put people at risk for disease, or that people with very early, undiagnosed Parkinson’s tend to stop using caffeine. But because of how caffeine acts on in the brain, and the relationship of those actions to other chemicals involved in Parkinson’s, it’s plausible caffeine could be playing a role itself, according to Dr. Postuma.

An earlier study into the effects of caffeine on incontinence showed that women with moderate incontinence shouldn’t be concerned. Although caffeine might have a shorter-term impact by making women need to urinate soon after eating or drinking something caffeinated as it increases the production of urine and may give some the urge to urinate, it wasn’t clear that a regular caffeine habit is tied to worsening incontinence over the long run.